Research On The Control Method Of Automobile Engine Active Mount

With the increasing demand for automobiles and the need for the development of new-generation automobiles,NVH has become one of the concerns of most consumers and car companies.The vibration caused by the engine is the main problem that needs to be solved for vehicle vibration.Engine vibration is first transmitted by the car suspension system to the connection and fastening devices around the car,and then transmitted to the car body by these devices,causing some major vehicle NVH problems.Vibration will affect people’s driving comfort,as well as the steering stability of the vehicle and the internal structure of the vehicle.After continuous conclusions by manufacturers and researchers in practice,the use of the suspension system can greatly reduce the transmission of vibration between the vehicle powertrain and the body.Therefore,the suspension system is widely used in automobiles to isolate the vibration caused by daily working conditions and special working conditions.Because the traditional passive suspension system is affected by its own performance,its damping characteristics are difficult to meet more and more stringent design requirements;for semi-active suspension systems,its damping characteristics can only alleviate the vibration and noise caused by the engine under specific driving conditions Problems,but it cannot meet the requirements of vibration isolation under multiple working conditions under driving conditions;with the continuous development of active vibration reduction control technology,whether it is in traditional fuel engines or new energy vehicles,active suspension systems will become the future The mainstream of suspension system design.This article considers the combination of hydraulic mount and electromagnetic actuator.Because hydraulic mount has a better effect on reducing engine vibration at low frequencies,electromagnetic actuators have active isolation at high frequencies.With the characteristics of vibration,an active mount with simple structure and good performance has been developed.The parameters of the suspension system are clarified by design,three-degree-of-freedom and six-degree-of-freedom simulation models are established for the active suspension respectively,the pros and cons of various actuators are analyzed and compared,the principle and characteristics of electromagnetic actuators are analyzed,and the focus is on Engine vibration,active suspension model system,and control strategy are studied.The specific development situation is as follows:First,analyze the working principle of the passive suspension system,and design the active output part on the basis of clarifying the internal structure.The electromagnetic actuator is added to the hydraulic suspension system,the dynamic model is established in the electromagnetic actuator,and the electrical theory is used to determine the main structural parameters of the electromagnetic actuator in combination with the control variable method,which is the subsequent establishment of the active suspension The system model provides support.Secondly,the engine excitation,road excitation and vibration isolation characteristics are analyzed,the excitation mathematical model is established,and the dynamic effect simulation analysis is carried out in the MATLAB/Simulink simulation environment.The two excitations are input into the three-degree-of-freedom suspension model,and the effects of engine individual excitation,road individual excitation and joint excitation under different working conditions are obtained,and the respective proportions of engine individual excitation and road individual excitation are obtained.Finally,PID controller and fuzzy controller are established for the three-degree-of-freedom active suspension system model.At the same time,combined with the theory of variable universe,the traditional fuzzy control can not be changed in the input and output variables of the traditional fuzzy control.At the same time,to improve the design of the fuzzy controller For the control effect,fuzzy inference is used to obtain the expansion factor of the universe,and a fuzzy controller with variable universe is used for the active suspension system.Based on the six-degree-of-freedom active suspension system model,PID control and fuzzy control are established.The neural network has parallel processing capabilities and independent calculation,transmission and feedback functions to optimize the controller.The control system effects of the two models are evaluated by the suspension system index and the suspension system index for evaluating the ride comfort of the vehicle.The results show that the optimized three-degree-of-freedom active suspension and six-degree-of-freedom active suspension model are in the system evaluation index.Compared with the passive suspension system,there are different degrees of improvement.This verifies the correctness of the simulation model and the feasibility of the active suspension system control strategy and other design schemes.